Bug#918545: qtdeclarative-opensource-src: FTBFS on x32: mis-detected as having amd64 JIT

[Thorsten Glaser <tg@mirbsd.de>]

Source: qtdeclarative-opensource-src
Version: 5.11.3-2
Severity: important

See also: https://buildd.debian.org/status/fetch.php?pkg=qtdeclarative-opensource-src&arch=x32&ver=5.11.3-2&stamp=1545865790&raw=0

src/qml/jsruntime/qv4global_p.h line 94 always triggers,
because x32 is detected as amd64 (Q_PROCESSOR_X86 and
Q_PROCESSOR_X86_64 are defined and QT_POINTER_SIZE is 8)
by qtbase5-dev (src/corelib/global/qprocessordetection.h).

Changing qprocessordetection to set QT_POINTER_SIZE to 4
for x32 won’t help because src/qml/jsruntime/qv4global_p.h
line 91 would then misdetect it as i386. (It would still
be more correct, but I don’t know if that would break
things that work, for now.)

I fear the best we can do is to add something around line
116 (blacklist):

#if defined(__x86_64__) && defined(__ILP32__)
// explicitly disable on x32 (amd64ilp32)
#undef V4_ENABLE_JIT
#endif